Method for promoting microalgae to produce biodiesel by treating landfill leachate with ozone at low temperature
By treating garbage leachate at low temperature and combining microalgae culture technology, the problem of difficult waste leachate in cold areas is solved, the production and resource utilization of clean energy is realized, and the oil content and biological content of microalgae are significantly improved. volume, reduce costs.
Patent Information
- Application Number
- CN202411370436.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2024-12-06
AI Technical Summary
Garbage leachate in cold areas is difficult to bio-utilize, and the existing treatment methods are low in resource utilization and are prone to secondary pollution, making it difficult to achieve the production of clean energy.
The waste leachate is treated with ozone at low temperature, and the toxicity is reduced by ozone oxidation, and the microalgae seed liquid is inoculated into the treated waste leachate, and the pH is adjusted and cultured, combining ultrasonic crushing and organic solvents to extract the oil and fat in algae cells. Realize the production of microalgae biodiesel.
Under low temperature conditions, the biochemical properties of the biomass resources of the waste leachate are improved, the cost of microalgae cultivation is reduced, the problem of difficult waste leachate is used, the production of clean energy is achieved, and the oil and fat of microalgae are significantly improved content and biomass.
Smart Images
Figure CN119082223A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of microalgae bioengineering, and in particular relates to a method for promoting microalgae to produce biodiesel by treating garbage leachate with ozone at low temperature. Background Art
[0002] Due to the cold climate, scarce resources and underdeveloped economy, energy supply in cold regions has become one of the bottlenecks restricting the economic and social development of the region. At the same time, the fossil energy crisis and the demand for new energy have accelerated the pace of finding alternative renewable energy. Biodiesel has become one of the ideal substitutes for fossil energy with its advantages of cleanliness, environmental protection, renewableness and biodegradability. As a raw material for biodiesel, microalgae has the advantages of fast growth rate, short growth cycle, high oil content and no competition with grain for arable land, and has attracted much attention from researchers at home and abroad. In addition, microalgae can also grow and produce using wastewater, industrial waste gas and other wastes, with good economic and social benefits. Therefore, the use of microalgae to produce bioenergy in cold regions can not only solve the problem of energy supply, but also bring environmental and economic benefits, and has important application prospects and development potential.
[0003] With the improvement of urbanization level, the output of landfill leachate increases year by year. Conventional treatment methods have low resource utilization and are prone to secondary pollution. With the advancement of waste-free city construction, how to use efficient technical means to recycle landfill leachate has attracted much attention. Using physical, chemical, biochemical and other means to transform landfill leachate into high value-added products has a relatively high degree of resource utilization, which can not only achieve waste treatment, but also create good economic benefits. Landfill leachate contains high concentrations of organic matter and nitrogen, which are suitable for the growth of microalgae. Using microalgae to treat leachate may be a promising alternative method that can simultaneously reduce pollutants and produce biomass. In addition, advanced oxidation treatment of landfill leachate can increase the degradation degree of macromolecular organic matter, reduce toxicity, and provide a better growth environment and oil production conditions for microalgae. Summary of the invention
[0004] The present invention overcomes the current situation that landfill leachate is difficult to utilize biologically and simultaneously realizes the production of clean energy, and provides a method for promoting microalgae to produce biodiesel by treating landfill leachate with ozone at low temperature.
[0005] A method for treating landfill leachate with ozone at low temperature to promote the production of biodiesel by microalgae is accomplished by the following steps:
[0006] 1. inoculating microalgae into a culture medium and culturing the microalgae to a logarithmic growth phase to obtain a seed solution;
[0007] 2. Treating the landfill leachate with ozone to obtain the landfill leachate after ozone oxidation;
[0008] 3. Inoculate the seed liquid into the landfill leachate after ozone oxidation, adjust the pH, and then culture until the late logarithmic growth period, and collect the algae cells by centrifugation;
[0009] 4. After freeze-drying the algae cells, ultrasonic disruption combined with organic solvents are used to extract the oil in the algae cells.
[0010] Beneficial effects of the present invention:
[0011] The method of the invention is simple to operate, and utilizes ozone oxidation under low temperature conditions to improve the biodegradability of biomass resources in landfill leachate to promote the production of bioenergy by microalgae, while also improving the stress resistance of microalgae under low temperature conditions to promote the production of bioenergy by microalgae.
[0012] The present invention utilizes the strong oxidizing effect of ozone to reduce the toxicity of landfill leachate, making it more suitable as a culture medium for the growth of microalgae to produce biodiesel, and reducing the cost of microalgae cultivation, overcoming the current situation that landfill leachate is difficult to utilize biologically, and simultaneously realizing the production of clean energy. The present invention is suitable for the application and promotion of resource utilization of landfill leachate coupled with microalgae production of biodiesel. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a bar chart comparing the biomass of microalgae R-56 at different temperatures of Example 1, Example 2, Comparative Example 1, Comparative Example 2 and Comparative Example 3;
[0014] Figure 2 It is a bar chart comparing the oil content of microalgae R-56 at different temperatures of Example 1, Example 2, Comparative Example 1, Comparative Example 2 and Comparative Example 3;
[0015] Figure 3 NH is the leachate after ozone treatment and microalgae growth. 4 + -N column comparison chart;
[0016] Figure 4 This is a bar chart comparison of the TP of landfill leachate after ozone treatment and microalgae growth;
[0017] Figure 5 This is a bar chart comparison of COD of landfill leachate after ozone treatment and microalgae growth;
[0018] Figure 6 This is a chromaticity bar chart comparison of landfill leachate after ozone treatment and microalgae growth. DETAILED DESCRIPTION
[0019] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes.
[0020] Specific implementation method 1: In this implementation method, a method for treating landfill leachate with ozone at low temperature to promote microalgae to produce biodiesel is completed according to the following steps:
[0021] 1. inoculating microalgae into a culture medium and culturing the microalgae to a logarithmic growth phase to obtain a seed solution;
[0022] 2. Treating the landfill leachate with ozone to obtain the landfill leachate after ozone oxidation;
[0023] 3. Inoculate the seed liquid into the landfill leachate after ozone oxidation, adjust the pH, and then culture until the late logarithmic growth period, and collect the algae cells by centrifugation;
[0024] 4. After freeze-drying the algae cells, ultrasonic disruption combined with organic solvents are used to extract the oil in the algae cells.
[0025] Specific embodiment 2: This embodiment is different from the specific embodiment 1 in that the microalgae in step 1 is Asterarcys quadricellulares R-56. The rest is the same as the specific embodiment 1.
[0026] The microalga Asterarcys quadricellulares R-56 is recorded in the document "Lipid production characteristics of a newly isolated microalga Asterarcys quadricellulare R-56 as biodiesel feedstock" published on February 9, 2023. The algae strain was isolated from the soil in Harbin City, Heilongjiang Province. After being diluted with pure water, it was spread on a BG-11 culture medium containing agar and cultured in a light incubator at a temperature of 25°C and a light intensity of 3500 lux. The above steps were repeated until the microalgae was purified.
[0027] Specific implementation method 3: This implementation method is different from specific implementation method 1 in that the temperature of ozone treatment in step 2 is 15° C., the concentration of ozone is 15 g / h, and the treatment time is 1 hour. Other aspects are the same as those of specific implementation method 1.
[0028] Specific embodiment 4: This embodiment differs from specific embodiment 1 in that the pH in step 3 is adjusted to 6.8-7. The rest is the same as specific embodiment 1.
[0029] Specific embodiment 5: This embodiment differs from specific embodiment 1 in that: the culture temperature in step 3 is 15°C, the light-dark ratio is 12h:12h, the illumination intensity is 3500-4000lux, and the shaking speed is 140-160r / min. Others are the same as specific embodiment 1.
[0030] Specific implementation method 6: This implementation method is different from the specific implementation method 1 in that the centrifugal speed in step 3 is 8000-10000 r / min and the time is 3-5 min. The rest is the same as the specific implementation method 1.
[0031] Specific embodiment 7: This embodiment is different from specific embodiment 1 in that the freeze drying in step 4 is to wash the cells with distilled water for 2 to 3 times, freeze them at -80°C for 12 hours, and then freeze-dry them in vacuum for 48 hours to collect freeze-dried algae powder. Others are the same as specific embodiment 1.
[0032] Specific embodiment 8: This embodiment differs from specific embodiment 1 in that: the organic solvent in step 4 is a chloroform-methanol mixed solution; the volume ratio of chloroform to methanol in the chloroform-methanol mixed solution is 2:1. Other aspects are the same as specific embodiment 1.
[0033] Specific implementation method 9: This implementation method is different from the specific implementation method 1 in that the power of the ultrasound in step 4 is 200 W. The rest is the same as the specific implementation method 1.
[0034] Specific implementation method 10: This implementation method is different from the specific implementation method 1 in that the crushing time in step 4 is 10 minutes. The rest is the same as the specific implementation method 1.
[0035] The following examples are used to verify the beneficial effects of the present invention:
[0036] Example 1: A method for treating landfill leachate with ozone at low temperature to promote the production of biodiesel by microalgae is accomplished by the following steps:
[0037] 1. Using 10 g / L glucose as the sole carbon source, inoculate microalgae R-56 into BG-11 medium and culture the microalgae to the logarithmic growth phase to obtain seed solution;
[0038] 2. Treating the landfill leachate with ozone to obtain landfill leachate after ozone oxidation; the ozone treatment temperature is 5°C, the ozone concentration is 15g / h, and the treatment time is 1h;
[0039] 3. Inoculate the seed liquid into the landfill leachate after ozone oxidation, adjust the pH to 6.8-7, and then culture until the late logarithmic growth period, and collect the algae cells by centrifugation; the culture temperature is 5°C, the light-dark ratio is 12h:12h; the light intensity is 3500-4000lux, the shaking speed is 140-160r / min; the centrifugal speed is 8000-10000r / min, and the time is 3-5min;
[0040] 4. The cells were washed 2 to 3 times with distilled water, frozen at -80°C for 12 hours, and vacuum freeze-dried for 48 hours. The freeze-dried algae powder was collected and the oil in the algae cells was extracted by ultrasonic disruption combined with an organic solvent; the organic solvent was a chloroform-methanol mixed solution; the volume ratio of chloroform to methanol in the chloroform-methanol mixed solution was 2:1; the power of the ultrasound was 200 W; and the disruption time was 10 minutes.
[0041] The results showed that in the experimental group with a reaction system temperature of 5°C, the biomass of microalgae was 0.30±0.03 g / L, and the obtained oil content was 44.71±4.25%.
[0042] Example 2: This example differs from Example 1 in that the temperature of the ozone treatment in step 2 is 15°C; the temperature of the culture in step 3 is 15°C.
[0043] The results showed that in the experimental group with a reaction system temperature of 15°C, the biomass of microalgae was 0.42±0.04 g / L, and the obtained oil content was 41.04±2.24%.
[0044] Comparative Example 1: The microalgae R-56 seed liquid was inoculated into the landfill leachate after ozone reaction at 25°C (ozone treatment temperature was 25°C), and the other methods were the same as those described in Example 1.
[0045] The results showed that under the reaction system and culture conditions of the control group at 25°C, the biomass of the microalgae was 0.45±0.02 g / L, and the obtained oil content was 29.25±3.02%.
[0046] Comparative Example 2: The microalgae R-56 seed liquid was inoculated into the landfill leachate after the ozone reaction at 35°C (the ozone treatment temperature was 35°C), and the other methods were the same as those described in Example 1.
[0047] The results showed that under the reaction system and culture conditions of the control group at 35°C, the biomass of the microalgae was 0.32 g / L and the obtained oil content was 27.70±0.43%.
[0048] Comparative Example 3: The microalgae R-56 seed liquid was inoculated into the landfill leachate after the ozone reaction at 45°C (the ozone treatment temperature was 45°C), and the other methods were the same as those described in Example 1.
[0049] The results showed that under the reaction system and culture conditions of the control group at 45°C, the biomass of the microalgae was 0.20±0.01 g / L and the obtained oil content was 13.76±2.22%.
[0050] The above results show that compared with the comparative example 1, when the ozone oxidation temperature and the microalgae culture temperature were 25°C, the microalgae biomass in Example 1, when the ozone oxidation temperature and the microalgae culture temperature were 5°C, was reduced by 0.12 g / L. In Example 2, when the ozone oxidation temperature and the microalgae culture temperature were 15°C, the biomass of the microalgae was 0.42 g / L, which was 0.03 g / L lower than that of the control group. In comparative example 2, when the ozone oxidation temperature and the microalgae culture temperature were 35°C, the biomass of the microalgae was reduced by 0.13 g / L compared with the control group. In comparative example 3, when the ozone oxidation temperature and the microalgae culture temperature were 45°C, the biomass of the microalgae was the lowest, at 0.20 g / L. In Examples 1-2, the oil content of the microalgae was higher than that of the control group, while in Comparative Examples 3-4, the oil content of the microalgae was lower than that of the control group, which were 27.70±0.43% and 13.76±2.22%, respectively. The above experiments show that both low and high temperatures inhibit the growth of microalgae. In contrast, the 15°C culture system has less inhibitory effect on the growth of microalgae, and can significantly increase the oil content of microalgae, and is closer to the temperature system for actual engineering applications.
[0051] Therefore, through Figure 1 , Figure 2 From the results of biomass, biomass yield and oil content of microalgae R-56, these results provide data support and theoretical support for the oil accumulation of microalgae R-56 by ozonating landfill leachate under low temperature conditions. It can be seen that under the reaction conditions of 15℃, the biomass of microalgae only decreased by 0.03g / L, while the oil content of microalgae increased by 1.40 times. Figures 3 to 6 The changes in the properties of landfill leachate after ozone treatment and microalgae growth can be seen from this. It can be seen that low temperature conditions can effectively promote the accumulation of oil in landfill leachate by cultivating microalgae, which is a feasible, economical and effective method to meet the basic needs of resource utilization of landfill leachate and production of bioenergy using microalgae in cold regions.
Claims
1. A method for promoting the production of biodiesel by microalgae by treating landfill leachate with ozone at low temperature. Features The method for treating landfill leachate with ozone at low temperature to promote the production of biodiesel by microalgae is completed in the following steps:
1. inoculating microalgae into a culture medium and culturing the microalgae to a logarithmic growth phase to obtain a seed solution; 2. Treating the landfill leachate with ozone to obtain the landfill leachate after ozone oxidation; 3. Inoculate the seed liquid into the landfill leachate after ozone oxidation, adjust the pH, and then culture until the late logarithmic growth period, and collect the algae cells by centrifugation; 4. After freeze-drying the algae cells, ultrasonic disruption combined with organic solvents are used to extract the oil in the algae cells.
2. The method of claim 1 for promoting the production of biodiesel by microalgae by treating landfill leachate with ozone at low temperature, Features The microalgae described in step 1 is Asterarcys quadricellulares R-56.
3. The method of claim 1 for promoting the production of biodiesel by microalgae by treating landfill leachate with ozone at low temperature, Features In step 2, the temperature of ozone treatment is 15° C., the concentration of ozone is 15 g / h, and the treatment time is 1 h.
4. The method of claim 1 for promoting the production of biodiesel by microalgae by treating landfill leachate with ozone at low temperature, Features In step 3, the pH is adjusted to 6.8-7.
5. The method of claim 1 for promoting the production of biodiesel by microalgae by treating landfill leachate with ozone at low temperature, Features The culture temperature in step 3 is 15° C., the light-dark ratio is 12h:12h; the light intensity is 3500-4000 lux, and the shaking speed is 140-160 r / min.
6. The method of claim 1 for promoting the production of biodiesel by microalgae by treating landfill leachate with ozone at low temperature, Features In step 3, the centrifugal speed is 8000-10000 r / min, and the time is 3-5 min.
7. The method of claim 1 for promoting the production of biodiesel by microalgae by treating landfill leachate with ozone at low temperature, Features The freeze drying in step 4 is to wash the cells with distilled water for 2 to 3 times, freeze them at -80°C for 12 hours, and then freeze-dry them in vacuum for 48 hours to collect freeze-dried algae powder.
8. The method of claim 1 for promoting the production of biodiesel by microalgae by treating landfill leachate with ozone at low temperature, Features The organic solvent in step 4 is a chloroform-methanol mixed solution; the volume ratio of chloroform to methanol in the chloroform-methanol mixed solution is 2:
1.
9. The method of claim 1 for promoting the production of biodiesel by microalgae by treating landfill leachate with ozone at low temperature, Features The power of the ultrasound in step 4 is 200W.
10. The method of claim 1 for promoting the production of biodiesel by microalgae by treating landfill leachate with ozone at low temperature, Features The crushing time in step 4 is 10 minutes.